yeah, I have an 88 325i just did a valve adjustment this morning. Mine has 175K miles on it and runs great. When was the last time a complete tune up was done? Major tune up means new plugs, cap, rotor, wires, fuel and air filter as well as a valve adjustment. I bet that would fix the issue. It always has on mine. Other than having coolant or oil leaks that are visable, which mine does not, that should do the trick....figure $300 for parts if you do it yourself, $700 if you take to a shop....good luck...cliff

actually, if had pick one thing first I would say fuel filter, but that seems too obvious I reckon.....but I swear, without some visable check engine code kind of thing or light I would just tune the darn thing up, lacking any other specific kind of error codes. the damn thing tattles on itself for damn no reason, brake light out, low coolant, whatever. If you have no telltale warning lights or check engine what else could it be? I swear that the 1988 BMW 325i engine is damn near bullet proof...possibly the best 6 ever built...and I mean this. Mine won't even leak or burn oil....ever...and I am serious, it has 175K miles on it and is still a monster....it's goofy how excellent this engine is.......

yeah, but I don't think it's valves...they may need adjusting but that wouldn't cause your issue...it sounds as if it's fuel delivery related. I would start with the fuel filter and work from there, myself....good luck

Bosch plugs are, and have been for a while, pregaped (look at the sticker on the end of each box, it'll say the gap and it is always correct) and do not require any adjustment. In fact, I wouldn't touch them at all other than putting the required fresh coat of new motor oil on the threads before installing them. Just coat the threads and screw em in...best of luck...cliff

well just in case, don't don't use Bosche plugs or any other part...every thing else is junk....if it calls for Bosche, use Bosche...it's just that simple...don't even consider anything else for these cars....it's false economy to the max....

yeah, here's an idea...take the airbox (whatever you mean by that) and see if the engine works right.....there is no way that an airbox (filter) will cause your problem...just take it off and see...power to your airbox? what the heck does that even mean? a powered airbox? i gotta say i have been working on BMWs for 25 years and have never, ever heard the phrase 'powered airbox'..really...that is kind of humorous to me personally...

theres your problem then, I had the same thing wrong with my vw one time, the maf came loose and popped off, idled but no rev. I remember someone saying something about cancer(the wires roting and grounding out) but that was from a crappy source. just take your test light and move up the wire until you find power.